Endoscope not only can be used as a medical optical instrument for diagnosis and treat but also can be used as industrial testing equipment, and has more than two hundred years of history. Although fiberscopes, electronic endoscopes, capsule endoscopes and ultrasound electronic endoscopes are now available, medical and industrial rigid endoscopes are still widely applied due to the advantages of excellent image quality, convenience for minimally invasive surgery, considerably lower price than soft endoscopes, and high temperature and pressure sterilization. However, relatively speaking, the rigid endoscope has too high price and poor imaging quality, is difficult to be widely popularized in outpatient examination, and hence will result in the etiological diagnosis delay of patients or even misdiagnosis.